Vertical type of double disc surface grinding machine

ABSTRACT

In a vertical type of double disc surface grinding machine, an object of this invention is to enable simple adjustment of a parallelism between a grinding surface of a lower grinding wheel and a work end face clamped by a clamping jig of a rotary table, even when a grinding wheel spindle axis is disordered. The vertical type of double disc surface grinding machine is equipped with a pair of grinding wheels  2  &amp;  3  opposing each other in vertical direction and fixed to a pair of vertical grinding wheels  4  &amp;  5  and a rotary table  15  holding a work W and supplying it to a grinding position A 1  located between the grinding wheels  2  &amp;  3,  and provided on the rotary table  15  with a work clamping jig  17  including a rotary shaft  63  which clamps the work W at a specified position and makes it spin itself. The table  15  and a bed  14  supporting its drive mechanism are supported by plural supporting legs  12  adjustable in their heights, so that front-to-back and right-to-left inclination angles can be adjusted in relation to horizontal level, and the supporting legs  12  are installed on a slide bed  11  slidable in horizontal direction.

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention

This invention relates to a vertical type of double disc surfacegrinding machine, in which a pair of grinding wheels opposing each otherin vertical direction are installed, a work is securely clamped to awork clamping jig provided on a rotary table, the work is supplied to agrinding position located between the grinding wheels, and both upperand lower surfaces of the work are ground simultaneously while the workis rotated around a spindle axis of the work clamping jig.

2. Prior Art

Generally, the vertical type of double disc surface grinding machine isequipped with a work supplying device suitable for a supplied workaccording to its size and type. In a work which can not be held at itscenter and is small in its rigidity such as a piston ring etc., forexample, a work supplying device is used wherein the work is held in awork holding hole formed on a thin-plate type rotary carrier in such away that both upper and lower end faces of the work are protruding fromthe hole respectively, and the work is supplied to the grinding positionbetween the grinding wheels while making the work spin itself by meansof a ring gear mechanism etc. Further, even when the work has a highrigidity such as a connecting rod or its shape is complicated not like arotation body, the work supplying device is used wherein the rotarycarrier including the above-mentioned work holding hole is provided inorder to hold the work in a freely rotatable manner.

On the other hand, for a work which is a rotation body as like anautomobile disc brake and has a constant rigidity so as not to bedeformed even when held at its central portion, a work supplying deviceis used wherein a central portion of the work is clamped to a clampingjig and the work is rotated together with the rotating spindle of theclamping jig so that the work is supplied to the grinding positionbetween the grinding wheels.

In general, the both upper and lower grinding wheels of the verticaltype of double disc surface grinding machine are so designed as to bemovable in vertical direction. The upper grinding wheel is equipped withan adjusting mechanism for adjusting an inclination angle of its spindleaxis, so that the wheel can be adjusted in its parallelism with respectto the lower grinding wheel. A spindle axis of the lower grinding wheelhas been fixed to its vertical position when shipped.

Problems of the Prior Art to be Resolved.

There may a case where a verticalness of the lower grinding wheelspindle axis is disordered due to a manufacturing error or shocks duringtransportation and manufacturing work, so as to produce a disorder ofhorizontalness of an upper grinding surface of the lower grinding wheel.Since the work is held in the work holding hole in the former worksupplying device, there is an allowance for the work to inclineaccording to the grinding surface of the grinding wheel in the holdinghole, and thereby a work grinding thickness can be kept uniform.

Since the work is clamped to the rotating spindle of the clamping jig inthe later work supplying device, there is no chance for the work toautomatically incline according to the grinding surface, so that thework grinding thickness can not be kept uniform to cause a decrease in agrinding accuracy. In addition, the lower grinding shaft must bedisassembled to adjust its verticalness by adjusting a bearing shim inorder to correct the grinding accuracy. Therefore, the correction ofaccuracy will become very troublesome.

An object of the invention of this application is to provide a verticaltype of double disc surface grinding machine which can simply improvethe grinding accuracy without requiring the troublesome shim adjustmentof the grinding spindle by enabling simple adjustment of horizontalposition of the work according to an inclination of the lower grindingwheel, even when a horizontalness of the lower grinding wheel, i.e. averticalness of the lower grinding wheel spindle, becomes out of orderto some extent.

SUMMARY OF THE INVENTION

An invention of this application as set forth in claim 1, in a verticaltype of double disc surface grinding machine which is equipped with apair of grinding wheels opposing each other in vertical direction andfixed to a pair of vertical grinding wheels and a rotary table holding awork and supplying it to a grinding position located between thegrinding wheels, and provided on the rotary table with a work clampingjig including a rotary shaft which clamps the work at a specifiedposition and makes it spin itself; is characterized in that

-   -   a bed supporting a table and its drive mechanism are supported        by plural supporting legs adjustable in their heights, so that        front-to-back and right-to-left inclination angles in relation        to a horizontal level can be adjusted.

An invention of this application as set forth in claim 2, in thevertical type of double disc surface grinding machine as cited in claim1; is characterized in that the supporting legs are provided for a slidebed which can be slidably adjusted in a horizontal direction.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a vertical type of double disc surface grindingmachine to which the invention of this application is applied.

FIG. 2 is a front view of FIG. 1.

FIG. 3 is a plan view of FIG. 2.

FIG. 4 is an enlarged sectional view take on a line IV-IV of FIG. 3.

FIG. 5 is a sectional view taken on a line V-V of FIG. 3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 is the side view of the vertical type of double disc surfacegrinding machine to which the invention of this application is applied.A pair of grinding wheels 2 & 3 opposing each other in verticaldirection and a not-shown power transmitting mechanism are housed in abody case 1, and a work supplying device 6 is installed adjacent to thebody case 1. For convenience of explanation, description will be made ona condition that a side where the work supplying device 6 is installedis assumed as a front side.

A lower grinding wheel 3 is secured to the top end of a vertical lowergrinding wheel spindle 5, an upper grinding wheel 2 is secured to thebottom end of an upper grinding wheel spindle 4 disposed on a spindleaxis 01 concentric with a lower grinding wheel spindle axis 02. The bothgrinding wheel spindles 4 & 5 are so designed as movable in the verticaldirection by elevating mechanisms respectively and are connected to thepower transmitting mechanism so as to rotate in reverse directions eachother.

The work supplying device 6 is composed of a base 10 supported by afloor surface and a front side of the body case 1, a slide bed 11supported on the base 10 in such a way as slidable in front-to-backdirection, three supporting legs 12 installed on the slide bed 11 andadjustable in their heights, a bed 14 supported by the supporting legs12, a rotary table (index table) 15 supported by the bed 14 in a freelyrotatable manner, a pair of work clamping jigs 17 installed on therotary table 15, and a clamping device 20 which clamps a work W placedon the work clamping jig 17 from above.

The clamping device 20 is composed of a pair of cylinders 22 includingclamping rods 21 extendable in lower direction, the respective cylinders22 are disposed on axes concentric with the rotating spindle axes 04 ofthe work clamping jigs 17 and fixed to a gate-type bracket 23 securedonto an upper surface of the rotary table 15. When the clamping rod 21is moved downward, the work W placed on the work clamping jig 17 ispushed down. Under the state where the work W is pushed down, theclamping rod 21 can be rotated together with the work W around theclamping jig spindle axis 04.

A protection cover 25 is disposed around the rotary table 15 and securedto the front side of the body case 1.

FIG. 2 is the front view (front-side view) of FIG. 1. A pair of guiderails 26 having trapezoidal sections are disposed on the base 10 at itsright and left sides. Slant faces of the guide rails 26 contact withslant faces formed on right and-left ends of the slide bed 11, so thatthe slide bed 11 is supported in such a way as slidable freely only infront-to-back direction. In addition, the slide bed 11 can be locked atany desired front-to-back position by a not-shown locking boltmechanism.

FIG. 3 is the enlarged plan view of FIG. 2. A bed is formed into arear-facing U-shape viewing from above, the three supporting legs 12 aredisposed at a laterally central portion of the front end part of the bed14, and at right and left end portions of the rear end part.

The both work clamping jigs 17 are disposed around a table spindle axis03 with 180-degrees phase difference put between them, so thatpositional change can be done between a grinding position A1 at thegrinding wheel side and a supplying and removing position A2 of theother side when the rotary table 15 is turned by half-turn

FIG. 5 is the enlarged sectional view taken on the line V-V of FIG. 3. Aportion of the bed 14 corresponding to the supporting leg 12 is formedinto a hollow structure having an U-shape cross section. The supportingleg 12 is composed of a base nut 30 secured to the slide bed 11, a bodybolt 33 secured to the base nut 30 in vertical position, an adjustingnut screwed into the body bolt 33, a spherical joint 32 contacting withthe adjusting nut 31 from above and holding a lower wall portion of thebed 14 from both upper and lower sides, and a lock nut 35 screwed intoan upper side of the spherical joint 32. In other words, the bed 14 canbe adjusted in its supporting height through the spherical joint 32 whenthe adjusting nut 31 is turned and adjusted by loosening the lock nut35, and the bed 14 can be adjusted in inclinations in front-to-back andright-to-left directions with respect to the horizontal level byadjusting the respective supporting heights of the supporting legs 12.Engaging holes 35 a and 35 b for inserting a turning tool are made onthe lock nut 35 and the adjusting nut 31, respectively.

An L-shaped bracket 27 is secured to the front end face of the base 10,a screw shaft 28 for moving the slide bed 11 in the front-to-leftdirection is supported by the bracket in a rotatable but unmovablemanner in an axial direction, the screw shaft 28 is screwed into afemale screw hole made on a front wall of the slide bed 11, and anoperation hand wheel 29 is fixed to the front end of the screw shaft 28.Namely, the slide bed 11 is so designed as to be movable in thefront-to-back direction through screw feed function by turning the screwshaft 28 using the operation hand wheel 29.

A vertical boss portion 40 is integrally formed at the rear end of thebed 14, and a spindle portion 42 of the rotary table 15 is freelyrotatably supported by the boss portion 40 through bearings 40. Atransmission case 44 is fixed to the bottom end of the boss portion 40,and an electric motor 45 is fitted to a front upper face of thetransmission case 44. In the transmission case 44, timing gears 51 & 52are secured to bottom ends of a motor shaft 50 of the electric motor 45and the spindle portion 42 of the rotary table 15 respectively, and atiming belt 53 is wound around the both timing gears 51 & 52.

FIG. 4 is the enlarged sectional view taken on the line IV-IV of FIG. 3.The work clamping jig 17 is provided with a cylindrical jig body 60fixed to an upper wall of the rotary table 15 in the vertical position,and a rotating shaft 63 supported in a rotatable but unmovable manner inthe axial direction in the jig body 60 through bearings 61 & 62. Apositioning pin 65 protruding upward and located on a spindle axisconcentric with the clamping jig spindle axis 04 is installed on anupper end face of the rotary shaft 63, and an annular work clamping bed64 is fixed on it. The annular work clamping bed 64 has a center hole 64a into which a boss portion Wa of the work W can be inserted. A diameterof the positioning pin 65 is so determined that the work boss portion Wacan fit on it.

An electric motor 70 for turning the work is fitted on the rotary table15 located toward a table center side from the work clamping jig 17, anda reduction gear 72 fixed to a motor shaft 71 of the electric motor 70engages with a gear 73 fitted to the bottom end of the rotating shaft 63within the rotary table 15. Namely, the rotating shaft 63 of theclamping jig 17 is rotated by rotation of the electric motor 70, and thework W clamped by the clamping rod 21 to the annular work clamping bed64 can thereby be rotated (itself) around the clamping jig spindle axis04.

[Function]

In FIG. 1, the respective work clamping jigs 17 are clamped in theirpositions between the rear-side grinding position A1 and the front-sidesupplying and removing position A2 through means of the half turningoperation of the rotary table 15 as mentioned above. At the supplyingand removing position A2, the already-ground work W is replaced by thenot-yet-ground work W by moving the clamping rod 21 upward, and thenot-yet-ground work W is clamped to the work clamping jig 17 by movingthe clamping rod 21 downward. While, at the grinding position A1, thework W is turned around the clamping jig spindle axis 04 and the surfacegrinding is carried out simultaneously on the upper and lower end facesby the upper and lower grinding wheels 2 & 3.

When the work replacement is completed at the supplying and removingposition A2 and the grinding of work is completed at the grindingposition A1; the upper and lower grinding wheels 2 & 3 are separatedapart from the upper and lower end faces of the work W located at thegrinding position A1 respectively, the clamping jig 17 at the grindingposition A1 is stopped its rotation, and the rotary table 15 is turnedby 180 degrees.

The not-yet-ground work W moved from the supplying and removing positionA2 to the grinding position A1 is rotated around the clamping jigspindle axis 04 integrally with the rotating shaft 63 and the clampingrod 21 through means of rotation of the rotating shaft 63 of theclamping jig 17 as shown by FIG. 4. The upper and lower grinding wheels2 & 3 get near to this work W under the rotating state, so that thewheels will grind the upper and lower end faces of outer periphery ofthe work W to specified amounts, respectively.

[Inclination Adjustment]

In FIG. 1, the heights of the three supporting legs 12 supporting thebed 14 are adjusted individually. Thus, front-to-back and right-to-leftinclinations of the bed 14 can be adjusted in relation to the horizontallevel, thereby parallelism of the lower grinding wheel spindle axis 02with the table spindle axis 03 and the clamping jig axis 04 can beadjusted, so that the upper and lower end faces of the work W can be setin parallel with the upper grinding surface of the lower grinding wheel3.

In the above inclination adjustment, it is ideal that the lower grindingwheel spindle 5 is in the perpendicular position and the upper grindingsurface of the lower grinding wheel 3 is in the horizontal position,then the position of the bed 14 is so adjusted that the table spindleaxis 03 and the clamping jig spindle axis 04 will become perpendicularand the upper and lower end faces of the work will become horizontal. Inactual case, however, the lower grinding wheel spindle axis 02 will beinclined against the perpendicular position within a range of allowableerror or sometimes may be inclined by more than the allowable error dueto vibrations during transportation or shocks produced during operation.In such a case, the table spindle axis 03 and the clamping jig spindleaxis 04 are adjusted in parallel with the lower grinding wheel axis 02and the upper and lower end faces of the work W are adjusted in parallelwith the upper end grinding surface of the lower grinding wheel 3, notby adjusting the perpendicularity of the grinding wheel 5 but byadjusting an inclination angle of the bed 14. In case of the uppergrinding wheel 4 too, an inclination angle of the upper grinding wheel 4is adjusted to an inclination angle of the lower grinding wheel 5 sothat the lower grinding surface of the upper grinding wheel will becomein parallel with the upper grinding surface of the lower grinding wheel3. Thereby, even if the perpendicularity of the lower grinding spindleaxis 02 becomes disordered, the grinding work may be carried out under astate where the grinding wheels 2 & 3 and the work W are in parallelpositions each other, and the grinding thickness of the work W is keptuniform to enable grinding operations on both surfaces with goodaccuracies.

[Front-to-back adjustment]

In case where a grinding area becomes large or small by changing a kindof the work, the work W at the grinding position A1 can be moved to anoptimum position with respect to the grinding wheels 2 & 3 by releasingthe locked state of the bed 14 of FIG. 1 and by adjusting the locationof the slide bed 11 in front-to-back direction through turning operationof the operation hand wheel 29.

ADVANTAGES OF THE INVENTION

(1) In the vertical type of double disc surface grinding machine whichis equipped with a pair of grinding wheels 2 & 3 opposing each other invertical direction and fixed to a pair of vertical grinding spindles 4 &5 and the rotary table 15 holding the work W and supplying it to thegrinding position A1 located between the grinding wheels 2 & 3, andprovided on the rotary table 15 with the work clamping jig 17 includingthe rotating shaft 63 which clamps the work W at the specified positionand makes it spin itself; the bed 14 supporting the table 15 and itsdrive mechanism are supported by plural supporting legs 12 adjustable intheir heights, so that the front-to-back and right-to-left inclinationangles in relation to the horizontal level can be adjusted. For thisreason, such a troublesome work as shim adjustment for the grindingwheel spindle axis 02 of the grinding wheel 3 becomes unnecessary evenif the spindle axis 02 of the lower grinding wheel spindle 5 should bedisordered from the vertical position. In addition, the upper and lowerend faces of the work W can be set in parallel with the grinding wheels2 & 3 by only carrying out the inclination adjustment of the bed 14 atthe side of work supplying device, so that the grinding accuracy can beimproved by the simple adjusting work. In other words, an uniformity ofthe work grinding thickness can be maintained.

(2) When the supporting legs 12 are installed on the slide bed 11 whichis slidably adjustable in horizontal direction, the grinding areacorresponding to respective works can be secured easily by onlyadjusting the slide bed 11 in front-to-back direction.

1. A vertical type of double disc surface grinding machine equipped witha pair of grinding wheels opposing each other in vertical direction andfixed to a pair of vertical grinding wheels and a rotary table holding awork and supplying it to a grinding position located between thegrinding wheels, and provided on the rotary table with a work clampingjig including a rotary shaft which clamps the work at a specifiedposition and makes it spin itself; in which a bed supporting a table andits drive mechanism are supported by plural supporting legs adjustablein their heights, so that front-to-back and right-to-left inclinationangles in relation to a horizontal level can be adjusted.
 2. A verticaltype of double disc surface grinding machine as set forth in claim 1; inwhich the supporting legs are provided for a slide bed that can beslidably adjusted in a horizontal direction.